Encyclopedia of Computer Science and Technology

Berners-Lee, Tim 43benchmarkA benchmark is a tool used to evaluate or compare theperformance of computer software or systems. Typically,this involves the design of a program (or suite of programs)that performs a series of operations that mimic “real world”activities. For example, computer processors (CPUs) can begiven calculations in floating-point arithmetic, yielding aresult in “flops” (floating point operations per second). Similarly,several different C-language compilers can be giventhe same files of source code and rated according to howquickly they produce the executable code, as well as thecode’s compactness, speed, or efficiency.Some examples of computer industry benchmarksinclude:• Dhrystone and Whetstone for integer and floatingpoint arithmetic, respectively• mIPS (millions of instructions per second) andMFLOPS (millions of floating point instructions persecond) for microprocessors• FPS (frames per second) for various types of graphics• 3DMark for three-dimensional graphics• test suites using Linpack and LAPACK for supercomputersThe devising of appropriate benchmarks is importantbecause they can help prospective purchasers decidewhich competing CPU, program development tool, databasesystem, or Web server to buy. Often the aspectsof systems that are highlighted in advertising are notthose that are most relevant to determining their actualutility. For example, CPUs are often compared accordingto clock speed, but a chip with a superior architectureand algorithm for handling instructions might actuallyoutperform chips with faster clock speeds. By puttingchips through their paces using the same arithmetic, datatransfer, or graphics instructions, the benchmark providesa more valid comparison.The most relevant benchmarks tend to focus on re-creatingreal-world use. Thus database systems can be comparedin their speed of retrieval or update of data records.Real-world benchmarks also help guard against manufacturers“tweaking” their systems to create artificially highbenchmark results. Nevertheless, benchmarks cannot beused mechanically. While a given industry may have an“industry standard” benchmark, and a given product maybe the highest performer using that test, the user must considerhow well that benchmark reflects the actual work forwhich the system or program is being purchased. Performance,however well benchmarked, is usually only one keyconsideration, with environment (such as network connections),reliability, security, ease of use, and of course costbeing other considerations.Further Readingcomp.benchmarks (USENET newsgroup).Jones, Capers. Software Assessments, Benchmarks, and Best Practices.Boston: Addison-Wesley, 2000.Netlib [repository for mathematical benchmarking software].Available online. URL: http://www.netlib.org/. Accessed May10, 2007.Berners-Lee, Tim(1955– )BritishComputer ScientistA graduate of Oxford University, Tim Berners-Lee createdwhat would become the World Wide Web in 1989 whileworking at CERN, the giant European physics researchinstitute. At CERN, he struggled with organizing the dozensof incompatible computer systems and software thathad been brought to the labs by thousands of scientistsfrom around the world. With existing systems each requiringa specialized access procedure, researchers had littlehope of finding out what their colleagues were doing or oflearning about existing software tools that might solve theirproblems.Berners-Lee’s solution was to bypass traditional databasesystems and to consider text on all systems as “pages”that would each have a unique address, a universal documentidentifier (later known as a uniform resource locator,or URL). He and his assistants used existing ideas of hypertextto link words and phrases on one page to another page(see hypertext and hypermedia), and adapted existinghypertext editing software for the NeXT computer to createthe first World Wide Web pages, a server to provide accessto the pages and a simple browser, a program that could beused to read pages and follow the links as the reader desired(see Web server and Web browser). But while existinghypertext systems were confined to browsing a single fileor at most, the contents of a single computer system, Berners-Lee’sWorld Wide Web used the emerging Internet toprovide nearly universal access.Between 1990 and 1993, word of the Web spreadthroughout the academic community as Web software waswritten for more computer platforms (see World WideWeb). As demand grew for a body to standardize and shapethe evolution of the Web, Berners-Lee founded the WorldWide Web Consortium (W3C) in 1994 and continues asits director. Together with his colleagues, he has struggledto maintain a coherent vision of the Web in the face of tremendousgrowth and commercialization, the involvementof huge corporations with conflicting agendas, and contentiousissues of censorship and privacy. His general approachhas been to develop tools that would empower the user tomake the ultimate decision about the information he or shewould see or divulge.Berners-Lee now works as a senior researcher at theMassachusetts Institute of Technology Computer Scienceand Artificial Intelligence Laboratory. In his original visionfor the Web, users would create Web pages as easily as theycould read them, using software no more complicated thana word processor. While there are programs today that hidethe details of HTML coding and allow easier Web page creation,Berners-Lee feels the Web must become even easier to